Security seals are commonly used to secure closure of utility meters, postal boxes, or other receptacles or devices where it is desired to prevent tampering therewith. Such seals may include a plastic body with a pair of apertures opening at one end of the body and a shackle formed of a piece of U-shaped wire having legs with reversibly bent end portions. When the seal is put into use, the shackle legs are first threaded through a structure to be secured, such as a retaining ring fitted around a cover for an electric meter. The shackle legs are then inserted into the body apertures whereby the reversibly bent end portions engage some form of inner structure of the body for permanent retention. A lateral pulling force on the shackle only forces the reversibly bent end portions into stronger engagement with the body. Thus, the shackle must be severed or otherwise broken, or the seal body must be damaged to open the seal.
In addition to the usual locking mechanisms, security seals typically include some form of tamper-indicating structure. Generally, tamper-indicating structures are designed such that any significant attempts to defeat or tamper with the seal will normally result in altering the seal in such a manner that the attempt will be readily detectable. For example, if any attempt to tamper with the seal is made, portions of the seal may be permanently damaged. Such damage in the seal is typically readily apparent, thereby indicating evidence of tampering.
Although such devices have served the purpose, they have not provided entirely satisfactory results, because some efforts to defeat such structures by picking have proved successful. One such method of picking involves inserting a picking tool into the seal body through openings or spaces where the shackle legs enter the seal body and deforming or cutting the shackle legs to an extent that the legs can be freely withdrawn from the sealed body, reformed, and later replaced in the seal body. Such tools also can be used to deform or cut parts of the seal body securing the shackle
Other tampering methods may include dissolving the shackle wire with acid, removing the security seal to tamper with the previously sealed meter, receptacle or device, and replacing the security seal using a replacement shackle.
Embodiments of a security seal according to the present disclosure provide improved security by discouraging tampering therewith by being configured in a manner such that any tampering therewith will be evident upon visual inspection of the security seal.